package miggy.dma;

import miggy.SystemModel;
import miggy.api.cpu.Size;
import miggy.api.memory.CustomRegisterObserver;
import miggy.memory.CustomRegisters;

/*
//  Miggy - Java Amiga MachineCore
//  Copyright (c) 2008, Tony Headford
//  All rights reserved.
//
//  Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
//  following conditions are met:
//
//    o  Redistributions of source code must retain the above copyright notice, this list of conditions and the
//       following disclaimer.
//    o  Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the
//       following disclaimer in the documentation and/or other materials provided with the distribution.
//    o  Neither the name of the Miggy Project nor the names of its contributors may be used to endorse or promote
//       products derived from this software without specific prior written permission.
//
//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
//  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
//  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
//  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
//  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
//  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
//  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// $Revision: 21 $
*/

public class SpriteChannel extends BaseDMAChannel
{
	int dmaEndTime;

	public SpriteChannel()
	{
		super("Sprite DMA Channel");

		SystemModel.REGS.addObserver(CustomRegisters.DDFSTRT, new CustomRegisterObserver() {
			public void update(int register, int value, Size size)
			{
				//if DDFSTRT < $34 then it eats sprite dma time
				dmaEndTime = value;
			}
		});

		reset();
	}

	public void reset()
	{
		enabled = false;
		dmaEndTime = 0x0034;	//0x0034 allows time for 8 sprites
	}

	public int doWork(int scanline)
	{
		if(!enabled)
			return 0;

		return 0;
	}


}
